Caliper gauge



Jly 6 1926.

EZ" s.

W AMES CALIPER. GAUGE Filed March 26, 1924 2 'Sheets-Sheeil l 4 I/ve/ Wai/'Wen Hwa/e6 1,591,260 w. AMI-:s l

CALIPER GAUGE Filed'lvlaron 26, 1924 2 Sheetsheet 2 July 6 1926.

Patented :luly 6, 1926.

v UNITI-:AD Es wAmN Alaior wurm, xassacnusar'rs. A ss'1e1von.1 To n. o. Amza'y oo.. or; WALTHAH, MASSACHUSETTS, `A oonroiwrronor lMaasaomrsiiz'iv'i?s.''j-

currar. ea'ucn.

Atpucauonfmd :kann as', 1924. sensing. roisseff My invention. relates to calipering instruments and particularly 'but not'4 exclusively to one for calipering the inside diameters of cylindrical vsurfaces'.

. l M inventi n will be best understood from the ollowing :description when read inthe light of the accomtpanying drawings showing one especific embo lmentv of my invention select .for illustrative 'purpgsea while the l eco of my invention will more particular y pointed out in the appended claims.

Y In the drawinglsir-'- Y' f Fig. 1 shows t e front'view of a caliper-f g instrument constructed according to my l invention; v f j Fig. 2 shows a rear view of the instrument;

strument; Fig. 4 is a section onthe line 4-4 o f Fig. 1; A ig. 5 is a'rear view onanenlarged scale with the back plate removed;

Fig. 6 isa section through the instrument -on the line 6-`6 of Fig. 5; and

' Fig. 7 isa section on the line Tf-7 of 'eferr'ng to the drawings which show thev embodiment.4 of my invention selected for a0 illustrative purposes, I provide a vframev for the operative parts ofthe instrument, which frame herein 1s in the form of avcasing having the cylindrical portion 1, the bottom plate3 and the top plate 5. The portion 1 ab vof the casin rotatably carries a ring 7 which supports.` a ens 8 and towhich is secured the graduated dial'plate 9 so that when the rin 1s rotated relatively' to the casingl the, dia

plate rotates with it, vthus enabling the dial plate to. be adjusted angularly'relatively to an indicator hand. 11. Extending through bushin 12 at diametrica-lly opposite portionso the casing are caliper members inthe-form of aligned. re

'45 .ciprocatory rods 13 which at their ends carry removable members 14 providing ealiperingv separation of the calipering points.

For lacing the calipering poi the drawings' the end portions 2 3 of the-base Aare bent at an Aangle tothe body portion thereof soasv to4 form' corners 25 which con- A points on the cylindrical surface.` Fig. 3 shows aside elevation ofthe in ints 15, the casing carrying mechanism` ereinafter to be describedffor causing'the indicator hand 11 to indicate the degree or'4 nts at cf liametrica y o posite points onthe cylindrical' measuredlrigidly secure tofthe backplatel 3 of thecasing by means. of screws. 17 la tongue 19 formed integrally with andprojectin upwardly from a 'base 21I whichlies. 1n a` p ane transverseto the axesofthe rods 13. 'As clearly lshown in Figs. 1Y and 2 of tact the walls of .the cylindrical surface .f to

be measured at opposite ends of a chord of the circle constituting. a transverse sectionjof said surfaceg'and as the "axes of the aligned rods 13 bisectthis ychord and are, normal thereto the calipering points 15 of said rods willv be placed at diametrically' opposite Referring particularly to Figs.'4, 5,16 and- 7 it will be noted that the indicator-hand. ll'is carried-ontheend of astem 27 whichf intermediate its .length is journaled `in the top plate5 andhas its' inner,` end in a bracket 29 'secured to the to A,lplate meansofscrews v3 1. The stem 2 carries.a gearv 33 in'mesh with a lar er gear35. so. that when thel latter is rotate the indicator hand 11 willvbe moved.- The earf35 is iixed- I l 'mounted on a spindle 37 w ch is mounted` r rotation in the .top plate 5 and Iin Vthe bracket 29 in 'a manner similar to 'thestemu 27.' 'At itsyinnerjend the vspindle 37 carries aI ar 39 in mesh .with a circular.- rack 41` 8l` l' formed on a rdl43,- and as will be obvious when the rod 43 is reciprocated theindicator' hand l1 will beturned--, .while rotation oithe rod 43 willnot a'ect the .indicator hand.`

For vtaking up lost motion between. the rack 41 and the gear39 and between the gear33 and the gear535 I provide a 'torsion spring` 45, the-gear 35- for this purpose being'split in-a planetransverseto :its axis assho'wn in Fig. 6 one vend ofthes ringbein .seculrtlal4 to thejadjacentihalf of t e ear` an the opposit'e'end toa fixed part o the casing. The rod 43 is reciprocated in responsetoj the relative motion between the rods 13. To

this end the. vrod- 43 is formed intermediate its length with a-spurngearportion 47, while, its end is reduced yin diameter and is'screw' threaded as indicated at 49. f Mounted-on the screw threaded portion 49is'a gear 51 of the same pitchv diameter as the gear of the rod.- The endportions of t e gear 51` `The gear 51 supports the left hand end of the rod 43 as viewed in Fig. 6, while its right hand end is supported for reciprocation and rotation in a bushing 57 carried by the cylindrical portion 1 of the casing. It will he noted by this construction vthat if the rod 43 is rotated and the gear 51 does not turn the rod will be moved longitudinally in a direction depending upon its direction of rotation. It will also be noted that if the gear 51 is rotated and uthe rod does not turn the rod will likewise be moved longitudinally in a direction depending upon the direction of rotation of the gear 51. If both the rod and gear are rotated the reciprocation of the rod will be proportional to the algebraic difference between the angular movements of the rod and gear, which means that if the rod and gear are rotated equal amounts in the same direction no reciprocat-ion of the rod 43 will result. 'i

In the present embodiment of my invention 011e of the calipering rods 13 rotates the shaft 43, while the other rod rotates the gear 5'1, the arrangement being such that.

equal movements of the rods 13 in the same direction rotate the rod 43 and gear 51 equal amounts in the same direction. To'this end the lower rod 13 as viewed in Figs. 4 and 5 is provided with rack teeth 58 meshing with the gear 47 which gea-r as heretofore ex-l plained is formed as part of the' rod 43, the rod being securely guided in its movements and being held in vmesh with the gear portion 47 by the lower bushing 12 through which the rod extends, and by the guide block 59 which has a square perforation 61 receiving the squared end portion 63-of the rod.- The upper rod 13 .which extends l through the upper bushing 12 has secured to its inner end one end of a cross bar 65, to the other end of which is secured the end of a rod 67 having formed thereon rack teeth 69 meshing with the gear 51. The cross bar extends through and is slidably supported in a slot 71 formed in a guide member 73, while lthe rod 67 is held in meshwith the rack by means of a plate 7 5 secured to the end of therod 67 by means of al screw 77 and slidably resting against the inside vsurface of the back plate 3 of the casing. i

From the above'construction it will be observed that each rod can be moved without imparting its motion to thc other 4rod, and that b oth rods can he moved the same amount in the same direction without affecting the position of the indicator hand relative to the dial, or what amounts to the same thing both rods may be held stationary and the casing reciprocated relatively to the rods without changing the relative position of the indicator hand to the dial plate. Alsol it will be observed that if only one rod moves the indicator hand will be moved land that if .there is any difference in motion between the two rods the ind-icatorhand will be moved a distance proportional to this difference.

For taking up the lost motion between the lower rod 13 and the gear 47 I provide a tor- .sion spring 79 carried by a collar 81 splined or otherwise secured in fixed angular relation to the rod 43, and as will be obvious to those skilled in the art one end of the spring is attached to the collar and the other is attached to a stationary part, as for example the top plate 5. For causing the rods 13 to tend to move outwardly and normally to separate the calipering points to their full extent and to hold the latter against the surface being calipered I provide tension springs 83 which have one of their ends attached to pins 85 carried by the rod 67 and lower rod 13 respectively and the other of their ends attached at 87 to the casing.

In practice the gauge readily lends itself to determining the variation of a piece of work from a standard. When used for this purpose the calipering points will be placed between the opposite surfaces of a set. gau e, and while in the gauge the dial plate maygbe rotated by turning the ring 7 to bring the zero reading of the dial plate under the index hand. If the instrument is then removed from the set gauge and applied to a piece of work to be measured the readings of the instrument will indicate the variation from the set gauge, the readings to the right of the zero mark indicatingv oversizes and the readings to the left indica-ting undersizes. The`dial plate may be calibrated in any convenient units, as for example thousandths of an inch.

Although I have described for purposes of i calipering'points diametrical y .opposite each other on such surfaces, said caliper members beingmovable relatively to each other and to said casing, indicating means carried by said casing, said indicating means having a movable member, and mechanism operated by said caliper members for moving said movable member of said indicating means a distance proportional to the algebraic difference in motion between said cahpering members.

2. A calipering instrument for measuring' the internal diameter of cylindrical surfaces and having in combination, a casing, caliper lOO A'members vhavingci'ilipering points, means;

' calipering points diametrica carried by said casing. for` Eositionmgsaid y opposite eachl other on such surfaces, said cali er members nism operated `by saidz cali ermembers'for carried by said casing vcalipering .points diametrically vopposite being movable relatively to feac other and to' `said casing, indicating'k means carriedby 4said casing, said 'indicating mean's having a movable member and a'normally stationaryl member, the" latter being^adjustable relatively to said movable member, and mechamoving sai'd movable'mem er of said vindicatingmeans a distance-proportional tothe ebraic diiference' in motion between said ip'ering membersgj 3. A calipering instrument for measuring the internal diameter'of cylindrical surfaces and having in combination, a casing, caliper" members fhaving calipering points, means for ositioningv said each other on' vsuch surfaces, said 'caliper members'being movable relatively to each other 1and to said casing, indicatingmeans carried by said casing, said indicating means ha f a movable member,'mechansm operated y said' caliper membersfor/moving said movable. member of said indicating' means a distance proportionaltov the algebraic difference in `motionbetw'een said calilpering members, and said mechanism permittingone caliper member to finove withl out impartng'motion't'o the other.

4. A. cali Vring instrument' for measuring thel interna diameter of cylindrical surfaces and havin in combinatiom a 'casing,'caliper members avmg calipering points, means calipering points dametrica y opposite eachother onxsuch surfaces, said caliper members carried vby said'ca'sing for ositioning said being movable relatively to veach other and to said casing, indicating means carried by 4said casing, said indicating .means having a movable member, 'diferential'mechanism operated by said calipermembers for movv king said movable member-of said indicating pering members, and said mechanism mittliig' one cahper member to move with'- `means a distance proportional to the algebraio difference 'in motion.l between said'calierout imparting motion to the other.v i

`5. A calipering instrument for measuring the internal diameter of cylindrical surfaces andA havin in combinatioma casing, caliper members aving calipering points, means carried by said casin for positioning-said ',calipering points' diametrically opposite eachy other 'onsuch surfaces, said caliper members rbein'gmovable relatively *to each other and toA said casing, indicating-'means carried'by said'casing, saidindicatin' means@l having a, movable member,'dilereiitia `mech 'anism 'including g a 4init and screw.- operated 4-by said' caliper'members for moving said v Tmovable member of said indicating means a one of which is `movable' for indicating ythe distance-proportional to theal ebraicdiferen ce in motion between saidca ipe'ringmemermitting one bers, and said mechanism outy imparting caliper member to move wit m'otion to the other.

' 6. Acaliperinginstrument for measuring the distance between spaced surfaces and `having in combination, an indicating means coi'npr'is'ln afrarne, vcaliper members in-l dependent y'i- 'movable 'relatively to yeach `other and tok said frame, said indicating means having a single movable member for indicating the degreeof separation of' said ,caliper members, and mechanism responsive `only to relative motion of said caliper members for-'moving saidl movable member and permitting -bodilymovement of said indicating means relatively to both' caliper meinbers 'without aiecting'the reading of said indicating'm'eans v"'vvhi-le said caliper 4members are inf' contact with opposed relatively stationary surfaces,

7.' A calipering i' the distance between spaced 'surfaces an having in combination', an indicating ,means comprising 'a frame, caliper members independently movable relatively t'o eachother 'and to said frame', 'said indicating ,means having la' graduated dial and a pointer only y 'degree of l'sepa'rzitionl of said 4caliper members, mechanism responsive only to relative "motion of 'said caliper members "for 'operating-said. indicating means comprisin of Vgears one of which is operativ -ne'cted for rotation t'o -`one o'f saidcaliper members and the otherof which is'operaa` pair l tively-connected' for rotation tothe other of' -said caliper members, and meansresponsive and-to said frame, said indicating means A yhaving a graduated dial and a pointer only one 'of' which is movable for indicating` the degree of separation of saidfcalipermembers, mechanism 'connecting both caliper members to 'said indicating means, said` Y' mechanism comprising ka pair of members 120 onel ofV which is operatively connected for rotation to one of saidcaliper members `and v the" other of which is operatively connected "for rotationto -the other of'said caliper j members', and means 4for 'transmitting to said indicating means a inotion'p'roportional t'o the'algebraic difference in motion" of the 'members'.y of'said' pair of` members.

. .9,Ac1ipering assument 'havipgf in. combination, indicatingfmeanshav1iig amovable indicator, a pairof caliper mem- 13 nst'rument for mea'suiiii .f

iosv bers, mechanism connectin said caliper members to said indicator or moving the latter a distance proportional to the algebraic difference in motion of said caliper members, and said mechanism permittmg motion of either of said caliper members without transmitting said motion to the other caliper member and permittingy bodily movement of said indicating means 4relatively to both caliper members without affecting the reading of said indicating means while said caliper members are in contact with opposed relatively stationary surfaces.

10. A calipering, instrument having. in combination, indicating means having a movable indicator, a pair of caliper members, differential mechanism comprising rotary gears lconnecting said caliper members to said indicator for moving the latter a distance proportional to the algebraic difference in motion of said caliper members, and said mechanism permitting motion of either of said caliper members without transmitting said motion to the other caliper member.

11. A calipering instrument, having in combination, indicating means having a. movable indicator, a pair of caliper members, mechanism connecting both caliper members to said movable indicator; said mechanism transmitting to said indicator no motion when said caliper members move equal distances in the same direction, said mechanism also transmitting to said indicator a motionproportional to the motion of either caliper member if the other remains stationary, and a motion proportional to the algebraic difference in motion of said caliper members if both move and permitting bodily movement of said indicating means relatively to both caliper members without affecting the reading of said indi- .eating means while said caliper members are 1n contact with opposed relatively stationary surfaces.

12. A calipering instrument, having in combinatlon, indicating means having a movable* indicator, a pair of caliper members, and differential mechanism comprising a palr of gears one of which is actuated by one of said caliper members and the other of which is actuated by the other of sald caliper members for transmitting a motion proportional to the algebraic difference in motion of said caliper members to said indicator.

13. A calipering instrument, having in combination, indicating means having a movable indicator, arpair of caliper members, differential mechanism actuated by both caliper members for transmittin a motion proportional to the algebraic di erence i-n motion of said caliper member to said indicator, said diiferential mechanism comprising a screw rotated in response to motion of one caliper member and a cooperating nut rotated in response to motion of the other caliper member.

14. A calipering instrument, having in combination, indicating means having a movable indicator, a pair of caliper' members, a screw mounted for longitudinal reciprocation, means for transmitting reciprocatory motion of said screw to said indicator, a rotatable nut on said screw, means restraining said nut against longitudinal reciprocation, and means for causing motion of one caliper memberrto rotate said screw and motion of the other caliper member to rotate said nut.

15. A calipering instrument, having in combination, indicating means having a movable indicator, a pair of caliper members, a rotatable screw threaded member carrying a relatively rotatable nut member, means for restraining one of said members against longitudinal motion and permitting the other to move longitudinally, means for transmitting the motion of such longitudinally movable member to said indicator,

and means for causing motion of one of said caliper members to rotate said screw and motion of the other caliper member to rotate said nut.

16. A calipering instrument, having in combination, indicating means having a movable indicator, a pair of caliper members, a screw threaded member, a rotatable gear` for rotating said screw threaded member, a rack cooperating with said rotatable gear and opera-ted by one of said caliper members, a second gear cooperating with a second rack operated by the other of said caliper members, said second gear having an axial screw threaded perforation receivin said screw threaded member ywhereby said second gear forms a nut cooperating with said screw threaded member, means for holding one of said gears against longitud-inal reciprocation and permitting the other gear to reciprocate longitudinally, means for transmitting the longitudinal motion of the longitudinally reciprocable gear to said indicator, and equal motions of said racks in the same direction rotating both gears through equal angles in the same direction.

17. A calipering instrument, having in combination, indicating means having a movable indicator, a pair of caliper members, ascrew threaded member, a rotatable gear for rotating said screw threaded member, a rack cooperating with said rotatable gear and operated by one of said caliper -members, a second gear cooperating with a second rack operated by the other of said caliper members,said second gear having an axial screw threaded perforation receivin said screw threaded member whereby sai second gear forms a nut cooperating with said screw threaded member, means for holding one of said gears against longitudinalreciprocation and permitting the other gear to reciprocate longitudinally, a third rack actuated by the reciprocation of the longitudinally movable gear, and means for transmitting the motion of said thirdrack to said indicator.

18. A calipering instrument, having in combination, -indicating means having a movable indicator, a pair of caliper members, a rotatable member, a rotatable circular rack for actuating said indicator, a screw threaded member, a secondlrotatable member forming a nut for said screw threaded member, means restraining one rotatable member against longitudinal motion and permitting the other to move longitudinally, the one having longitudinal motion being connected to said circular rack, and ,means for causing equal motions of said caliper member to rotate said rotatable members the s ame amount.

19. A calipering instrument, having in combination, indlcating means having a relatively movable pointer and a graduated member one of which is normally stationary relatively to ,said indicating means, -a pair of caliper members movable relatively to each other and to said indicating means, mechanism responsive to motion of said caliper members for causing said indicating means to indicate the degree of separation of said caliper members, and said mechanism permitting bodily movement of said indieating means relatively to both caliper members wit-hout affecting the reading of said indicating means.

In testimony whereof, I have signed my name to this specification.

WARREN AMES. 

